Proposals that would allow Ofsted to inspect churches, youth clubs and other out-of-school settings were dealt a blow on Monday as a poll revealed only one in four MPs thought they would make Britain safer.

The plans were introduced as part of the government's wider counter-extremism strategy and would force any group teaching under-19s for over six hours a week, including youth groups and scout clubs, to register and face inspections.

The Prime Minister had sought to allay concerns from Christians and a number of MPs from all parties by promising Sunday schools would not be regulated and the inspectors would only target places where children would receive "intensive education".

However a ComRes poll published today revealed over half of MPs thought the proposal would "threaten legitimate and reasonable activities" and two-thirds agreed with the statement: "While the need to tackle extremism is clear, the proposal defines too widely the activities which would be covered by it."

The research also showed politicians across all parties were divided on whether they thought the safety would be enhanced with one in four agreeing it would and 37 per cent disagreeing.

The study was commissioned by The Christian Institute and director Colin Hart said it showed MPs were "widely concerned about these draconian proposals".

"They recognise that the extension of these meddling and intrusive inspections will have a serious effect on many small community groups, such as bell ringers, sports and youth clubs, scouts and guides – even amateur dramatics. These measures will almost certainly force some of them to close."

The research also revealed over a third of MPs questioned thought the inspection body could not be trusted to conduct these checks in a "fair, reasonable and measured way". Among Conservative MPs this suspicion rose to 45 per cent.

When the policy was first introduced in December churches and other Christian groups feared they could face sanctions for teaching marriage was between one man and one woman. It followed warnings about a small number of Muslim madrassas where, according to David Cameron, children have their "heads filled with poison and their hearts filled with hate".

Among the survey of 150 MPs published today,over half warned the policy seemed "panic-driven" and risked "the freedom of law-abiding citizens" with 50 per cent agreeing and only 31 per cent disagreeing.

Hart concluded: "Day by day this policy unravels. As MPs have rightly reflected, the policy is rushed, ill-judged and could be counter-productive. How on earth does subjecting the scouts, bell ringers and sports clubs to bureaucratic inspections – possibly forcing them to close – promote British values and combat extremism?"